The present invention relates to a raceway fitting for introducing a conduit, electrical wiring or the like into a duct or raceway of a surface mounted duct system. More specifically, the invention relates to a conduit adapter assembly having a base and a cover detachably coupled to each other by snap-fitting complementary parts. The base has a reverse taper on the receiving area for the snap portions on the cover, which acts as a cam to return the fitting or box cover to its original position, when the cover is dislodged due to an outside force or impact.
Surface mounted duct systems for enclosing conduit, electrical wiring and the like are known. A typical duct system includes a plurality of raceway runs, some of which are joined at various locations by junction enclosures. The precise configuration of each duct system, including the raceway sizes, lengths and locations, and the number and type of junction enclosures, is determined by site-specific wiring layouts. Sometimes, one or more junction enclosures are used to introduce the conduit into one of the raceway runs of the duct system.
Enclosures serving as junctions and/or conduit adapters must cooperate with their corresponding raceways to completely conceal and protect the conduit running therethrough. At the same time, the enclosures and raceways must present an aesthetically pleasing appearance since the entire duct system is typically mounted on an exposed surface. To maintain an aesthetically pleasing appearance, duct systems have employed tight-fitting connections between raceways and junction enclosures and between the separate portions of the junction enclosures.
Additionally, the connections between the portions of the junction enclosures must stay coupled together during a low temperature impact test. Many of the conventional raceway covers separate during this test, resulting in failure of the cover. One conventional method to resolve this problem is to increase the components"" wall thicknesses, which creates more spring resistance. Another conventional method is to deepen the snap engagement, which results in more resistance force. These modifications make assembly difficult and add cost of materials to the production.
Examples of prior art raceways and junctions include U.S. Pat. No. 6,188,018 to Benito-Navazo; U.S. Pat. No. 5,747,733 to Woods; and U.S. Pat. No. 5,300,731 to DeBartolo, Jr. et al., each of which is herein incorporated by reference.
Thus, there exists a need to provide an improved conduit adapter assembly, which can pass a low temperature impact test.
Accordingly, a primary object of the present invention is to provide a raceway fitting capable of introducing a conduit into a raceway of a duct system.
Another object of the present invention is to provide a raceway fitting capable of forming a junction between different runs of raceway or duct.
Another object of the present invention is to provide a raceway fitting capable of passing a low temperature impact test.
Another object of the present invention is to provide a raceway fitting capable of recoupling a housing cover to a base after a low temperature impact test and avoiding uncoupling thereof.
Still another object of the present invention is to provide a raceway fitting capable of recoupling a housing cover to a base after a low temperature impact test using a tapered portion on at least one portion of the housing and avoiding uncoupling thereof.
Yet another object of the present invention is to provide an enclosure for a duct system that is relatively simple in construction and cost effective to produce.
The foregoing objects are basically obtained by providing a raceway fitting, including a first housing portion having a base, a first wall and a second wall and a first coupling member on the first wall. The first coupling member has a tapered surface with first and second ends, the tapered surface extending from an obtuse angle from the first wall. The assembly further has a second housing portion with a first side portion and a second side portion, a second coupling member on the first side portion, the second coupling member having a first edge and a second edge. When coupling the first and second housings portions together, the first edge of the second coupling member engages the tapered surface of the first coupling member, adjacent the first end and traverses the tapered surface in the direction of the second end, to facilitate the coupling thereof.